Interleaved 2 of 5 | ITF-14 Barcode FAQ & Tutorial

Interleaved 2 of 5 Barcode Overview

Interleaved 2 of 5 (ITF) is a numeric only barcode used to encode pairs of
numbers into a self-checking, high-density barcode format. In this symbology,
every two digits are interleaved with each other to create a single symbol. If a
number string containing an odd number of digits needs to be encoded, a leading
zero must be added to produce an even number of digits in the Interleaved 2 of 5
barcode. In many cases, the
Code 128 barcode
offers an advantage over the ITF barcode because it encodes even and odd numbers
of digits, as well as letters and symbols, with nearly equal density.

The
symbology of the character set consists of barcode symbols representing numeric
characters 00 to 99, the space character and start/stop characters. The complete
printed barcode consists of a leading quiet zone, a start pattern, interleaved
symbols representing data, an optional
MOD 10 check character, a stop pattern, a
trailing quiet zone and an optional bearer bar pattern surrounding the entire
symbol.

The bearer bar versions are provided to meet certain specifications such
GS1 ITF-14. Some of these specifications state that only horizontal bearer
bars along the top and bottom of the barcode symbol are necessary, the
bearer bar versions provided in this package completely surround the barcode
which meet or exceed any bearer bar requirement.

USS Interleaved 2 of 5 (Uniform Symbology Specification Interleaved 2 of
5) is the published specification for Interleaved 2 of 5. All IDAutomation
products support the published specification. Several standards exist that
dictate how ITF barcodes should be generated for certain implementations; a
few of these include ITF-14, EAN-14, SCC-14, GTIN,
VCA OPC and DUN14.

ITF-14 is the GS1 System's only use of Interleaved 2 of 5 and it is only
used to encode the
GTIN as a 14 digit number. It is commonly used on shipping boxes and
containers.

Bar Height:The minimum recommended bar height for an
ITF-14 Barcode is 32mm (1.25") when used in General Distribution Scanning
environments (automated scanning). For all other scanning applications, the
height should be as high as possible. In no case shall the bar height be
less than 13mm (.5"). While 13mm (.5") is the minimum height for barcodes
not being scanned in an automated scanning environment, every effort should
be made to increase the bar height to 32mm (1.25") as possible.

Bar Width (X Dimension):The X Dimension is the width
of the smallest bar in the symbol. In automated scanning environments, the X
Dimension should be 0.495mm - 1.02mm (20 to 40mils). For all other scanning
applications, the acceptable range is 0.250mm to 0.495mm (10-20mils).

Bar Width Ratio (N Dimension):Bar width ratio (also
known as the Narrow to Wide ratio or the N Dimension) is the difference of
bar widths between the wide bars and the narrow bars in an ITF-14 Barcode.
The acceptable range is 2.25:1 to 3:1. The IDAutomation
Interleaved 2 of 5 Barcode Fonts have an N dimension of 2.75:1.

When using the IDAutomation Interleaved 2 of 5 Barcode Fonts, the
following chart provides the recommended font name and size to use.

Environment

Font Name

Point Size

X Dimension

Height

Automated Scanning

IDAutomationI25XL

28

.495mm (20 mils)

38mm (1.5")

General Scanning

IDAutomationI25L

14

.25mm (10 mils)

14mm (.55")

Bearer Bar and Checksum Options

The
purpose of "Bearer Bars" and the checksum is to reduce the possibility of
misreads or short scans that may occur when a skewed scanning beam enters or
exits the barcode symbol through its top or bottom edge. Bearer Bars should be a
constant minimum thickness of twice the width of the narrow bar, placed directly
against the top and bottom of the symbol bars. The bearer bars should completely
surround the symbol, including the Quiet Zones, which are a minimum of 10 times
the X dimension, which is the width of the narrow bar of the barcode. Many
mandates for i2of5 require Bearer Bars and a MOD
10 Checksum. Some specifications state that only horizontal bearer bars
along the top and bottom are necessary, however, it is better to use bearer bars
that completely surround the barcode because it meets or exceeds any bearer bar
requirement.

Printing ITF Barcodes

Several
Barcode Integration
Guides are available that suggest one or more barcode printing options.
These integration options should be examined to determine whether to use barcode
components, applications or barcode fonts for the printing of Interleaved 2 of 5
barcodes. A few of the
Barcode Integration
Guides offered include the following:

Featured Product:

The IDAutomation
Universal Barcode
Font is a unique product that excels at generating ITF barcodes on multiple
operating systems and locales, including Double Byte versions of Windows. This
product overcomes the obstacles that sometimes occur when printing the
Interleaved 2of5 barcode font outside of the USA. It also provides three
different narrow to wide ratios: 2, 2.5 and 3.

Reading & Scanning

The most common
method of reading barcodes is with a
barcode scanner. Most of the
barcode scanners recommended by IDAutomation perform keyboard emulation and
receive power from the USB port, so that no external power supply is required.
When a barcode is scanned using keyboard emulation, the data scanned appears at
the cursor as if it had been typed in from the keyboard.

To manually create a barcode encoding the number 772233 with the chart below,
use the following process:

Include the START character: Ë

Include the data characters from the char columns that represent 2
numbers from the ITF code column. For example, the numbers of 77 22 33 is
represented in characters: n7B

Include the STOP character: Ì

Combine the resulting text string with the barcode font: Ën7BÌ

The "ITF Code" column lists the character that the scanner will read
for the associated symbol. The columns ASCII, Char
and Unicode designate the location in either
ASCII or Unicode where the barcode symbol for the character resides in the
barcode fonts. When the Latin-1 codepage is not being used, it is suggested to
use the Universal
Barcode Font Advantage, which creates the ITF barcode as a font in any
codepage and operating system in the same way.

ITF Barcode Character Set Chart

ITF Code

ASCII *

Unicode *

Char

ITF Code

ASCII *

Unicode *

Char

na

0032

0020

space

51

0084

0054

T

00

0033

0021

!

52

0085

0055

U

01

0034

0022

"

53

0086

0056

V

02

0035

0023

#

54

0087

0057

W

03

0036

0024

$

55

0088

0058

X

04

0037

0025

%

56

0089

0059

Y

05

0038

0026

&

57

0090

005A

Z

06

0039

0027

'

58

0091

005B

[

07

0040

0028

(

59

0092

005C

\

08

0041

0029

)

60

0093

005D

]

09

0042

002A

*

61

0094

005E

^

10

0043

002B

+

62

0095

005F

_

11

0044

002C

,

63

0096

0060

`

12

0045

002D

-

64

0097

0061

a

13

0046

002E

.

65

0098

0062

b

14

0047

002F

/

66

0099

0063

c

15

0048

0030

0

67

0100

0064

d

16

0049

0031

1

68

0101

0065

e

17

0050

0032

2

69

0102

0066

f

18

0051

0033

3

70

0103

0067

g

19

0052

0034

4

71

0104

0068

h

20

0053

0035

5

72

0105

0069

i

21

0054

0036

6

73

0106

006A

j

22

0055

0037

7

74

0107

006B

k

23

0056

0038

8

75

0108

006C

l

24

0057

0039

9

76

0109

006D

m

25

0058

003A

:

77

0110

006E

n

26

0059

003B

;

78

0111

006F

o

27

0060

003C

<

79

0112

0070

p

28

0061

003D

=

80

0113

0071

q

29

0062

003E

>

81

0114

0072

r

30

0063

003F

?

82

0115

0073

s

31

0064

0040

@

83

0116

0074

t

32

0065

0041

A

84

0117

0075

u

33

0066

0042

B

85

0118

0076

v

34

0067

0043

C

86

0119

0077

w

35

0068

0044

D

87

0120

0078

x

36

0069

0045

E

88

0121

0079

y

37

0070

0046

F

89

0122

007A

z

38

0071

0047

G

90

0123

007B

{

39

0072

0048

H

91

0124

007C

|

40

0073

0049

I

92

0125

007D

}

41

0074

004A

J

93

0126

007E

~

42

0075

004B

K

94

0197

00C5

Å

43

0076

004C

L

95

0198

00C6

Æ

44

0077

004D

M

96

0199

00C7

Ç

45

0078

004E

N

97

0200

00C8

È

46

0079

004F

O

98

0201

00C9

É

47

0080

0050

P

99

0202

00CA

Ê

48

0081

0051

Q

START

0203

00CB

Ë

49

0082

0052

R

STOP

0204

00CC

Ì

50

0083

0053

S

* Some
ASCII
and Unicode values in this chart are unique to IDAutomation
Interleaved 2 of 5 Barcode Fonts. The specification for Interleaved 2of5
does not specify the actual location of ASCII and Unicode values for the symbols
in a font.

Since Interleaved 2 of 5 requires an even number of digits to "interleave"
numbers, the data encoded must be an odd number of digits when using a check
character, thus resulting in the required even number of digits.

The standard method of obtaining the check character (referred to as USS
Interleaved 2 of 5 MOD 10) is obtained by performing the following calculation:

Add up the odd numbers in the code.

Multiply the sum of the odd numbers in the code by 3.

Add up the even numbers.

Determine the number that when added to the sum, will produce a multiple of
10.

For example, the check digit for 123456789 is 5 because
(3*(1+3+5+7+9))+(2+4+6+8) = 95 and 95 + 5 =100.

Identcode & Leitcode Checksum Calculations:

The calculation for Identcode and Leitcode applications is
similar to USS Interleaved 2 of 5 MOD 10, except that even numbers are
multiplied by 9 and odd numbers by 4. For example, the check digit for
12345678901 would be "6" because (4*(1+3+5+7+9+1))+(9*(2+4+6+8+0)=284 and 284 +
6 = 290.

The following examples create a barcode with IDAutomation
Interleaved 2 of 5 Barcode Fonts in the Latin-1 codepage, which is the
default setting in the USA. When the Latin-1 codepage is not being used, or when
using a Mac, it is suggested to use the
Universal Barcode
Font, which creates ITF and many other barcode types from a single font in
any codepage and operating system.